Fly away flies!

It's July and it's raining heavily outside!
You're at home since the roads/rails are sleeping with the fishies and you can't go nowhere else.
You get all cozy your couch, munching on some delicious hot onion bhajjiyas and sipping on a mug of tea (well tea is my fav drink!; "Mocha" for you coffee lovers) and reading your favorite novel.
It's so *bzzzzzzzn* bhah!...
It's so calm an *BZZZznnnnn* bhack!!
hmphm..
It's all so calm and seren.. *BZZZZZZZMMTTT* bhwahhh!! DAMN YOU F'ING FLY!!!

Ok, so I've managed to get a decent build-up. Uhm, if I haven't, stay with me anyway, this is useful.
So the damned fly keeps crawling on your feet or hovering on your food, rubbing it's scrawny hands/legs like some evil villain and then when you're just about to squat it, it teasingly flies away while you squat something that shouldn't have been.
So here's the solution,
Repel flies with a bag of water!
LifeHacker feeds to the rescue again. LH explains how this works;

Evidently, houseflies, being highly edible and defenseless, are nervous types, and don't like to sit still when they see something moving nearby, because it could be a predator. The water bag acts a bit like a lens—try it some time—in which the movements of people in the area are reflected. Even if the fly is too far from the action to see it directly, it can see a shifting of light and dark in the water bag, which it interprets as nearby movement, and it will fly away from the bag.

Simple. Nu?
Fly away then mateys...